Faced the problem a few years ago, and used **[pg2mysql][1]**

**EDIT 21 july 2019** : **[this fork][2]** seems a better option (patches, light maintenance)

  [1]: http://www.lightbox.ca/pg2mysql.php
  [2]: https://github.com/ChrisLundquist/pg2mysql

You can use the [MySQL Workbench](http://dev.mysql.com/downloads/workbench/) which can import from a variety of database types, including Postgres.


[Dbeaver][1] is the perfect solution for painless migration, column to column mapping, character encoding and also open source.


  [1]: http://dbeaver.jkiss.org/

What&#39;s the difference between the `IN` and `MEMBER OF` JPQL operators?

What&#39;s the difference between the IN and MEMBER OF JPQL operators?

I&#39;m new to the new query interface of ActiveRecord so I&#39;m still figuring things out.  

I was hoping someone could explain the difference between using a `scope` in an ActiveRecord model and just using a class method (ie `self.some_method`)

From what I can gather, a scope is always expected to return a relation, whereas a class method doesn&#39;t necessarily have to.  Is this true?

For instance, I thought it would make sense to do something like:

    class Person
      scope :grouped_counts, group(:name).count
    end

But this doesn&#39;t work.  I get this error:

    ArgumentError: Unknown key(s): communicating, failed, matched, unmatched
    	from /Users/bradrobertson/.rvm/gems/ruby-1.9.2-p180@influitive/gems/activesupport-3.0.5/lib/active_support/core_ext/hash/keys.rb:43:in `assert_valid_keys&#39;
    	from /Users/bradrobertson/.rvm/gems/ruby-1.9.2-p180@influitive/gems/activerecord-3.0.5/lib/active_record/relation/spawn_methods.rb:110:in `apply_finder_options&#39;
    	from /Users/bradrobertson/.rvm/gems/ruby-1.9.2-p180@influitive/gems/activerecord-3.0.5/lib/active_record/named_scope.rb:110:in `block in scope&#39;
    	from (irb):48
    	from /Users/bradrobertson/.rvm/gems/ruby-1.9.2-p180@influitive/gems/railties-3.0.5/lib/rails/commands/console.rb:44:in `start&#39;
    	from /Users/bradrobertson/.rvm/gems/ruby-1.9.2-p180@influitive/gems/railties-3.0.5/lib/rails/commands/console.rb:8:in `start&#39;
    	from /Users/bradrobertson/.rvm/gems/ruby-1.9.2-p180@influitive/gems/railties-3.0.5/lib/rails/commands.rb:23:in `&lt;top (required)&gt;&#39;
    	from script/rails:6:in `require&#39;
    	from script/rails:6:in `&lt;main&gt;&#39;
    r

It does however work as a class method

    def self.grouped_counts
      group(:name).count
    end

I&#39;m interested to know peoples&#39; thoughts on when to use scopes and when to use class methods.  Am I correct in assuming that a scope must always return a relation, but a class method can return whatever it wants?

ActiveRecord Rails 3 scope vs class method

I have changed database from [tag:PostgreSQL] to [tag:MySQL], but I don&#39;t know how to transfer data from one to other.

Does anyone know any command by which I can copy/migrate my database from [tag:PostgreSQL] to [tag:MySQL]?

Migrate database from Postgres to MySQL

<p>I have changed database from [tag:PostgreSQL] to [tag:MySQL], but I don't know how to transfer data from one to other.</p>
<p>Does anyone know any command by which I can copy/migrate my database from [tag:PostgreSQL] to [tag:MySQL]?</p>


I want to move table from one schema to another schema in mysql , can anybody tell me how can I do this .


move table from one schema to another schema ?

I had set the MySQL path, but still getting the same error. Please let me know whether I followed the correct one or not.

MySQL location is: `C:\Program Files\MySQL\MySQL Server 5.0\bin`

In Windows, system variables I had set the path as:

- variable name: `MYSQL_HOME`
- variable value: `C:\Program Files\MySQL\MySQL Server 5.0\bin`

For PATH setting:

- variable name: `PATH`
- variable value: `.;%JAVA_HOME%\bin;%MYSQL_HOME%\bin...`

If it is not the correct one, please let me know the correct path and its settings.

mysql is not recognised as an internal or external command,operable program or batch

In MySQL, I want to be able to search for `&#39;31 - 7&#39;`, when another value = `&#39;7 - 31&#39;`.  What is the syntax that I would use to break apart strings in MySQL?  In PHP, I would probably use `explode(&#39; - &#39;,$string)` and put them together.  Is there a way to do this in MySQL?  

Background: I&#39;m working with sports scores and want to try games where the scores are the same (and also on the same date) - the listed score for each team is backwards compare to their opponent&#39;s database record.  

The ideal MySQL call would be:

    Where opponent1.date  = opponent2.date
      AND opponent1.score = opponent2.score

(`opponent2.score` would need to be `opponent1.score` backwards).


Equivalent of explode() to work with strings in MySQL

I&#39;m doing a pagination feature using Codeigniter but I think this applies to PHP/mySQL coding in general.

I am retrieving directory listings using offset and limit depending on how many results I want per page. However to know the total number of pages required, I need to know (total number of results)/(limit). Right now I am thinking of running the SQL query a second time then count the number of rows required but without using LIMIT. But I think this seems to be a waste of computational resources. 

Are there any better ways? Thanks!

EDIT: My SQL query uses WHERE as well to select all rows with a particular &#39;category_id&#39;

Find total number of results in mySQL query with offset+limit

Is it possible to include the headers somehow when using the MySQL `INTO OUTFILE`?


Include headers when using SELECT INTO OUTFILE?

    SELECT id, amount FROM report

I need `amount` to be `amount` if `report.type=&#39;P&#39;` and `-amount` if `report.type=&#39;N&#39;`. How do I add this to the above query?

&#39;IF&#39; in &#39;SELECT&#39; statement - choose output value based on column values

I currently have a live redis server running on a cloud instance and I want to migrate this redis server to a new cloud instance and use that instance as my new redis server. If it were MySQL, I would export the DB from the old server and import it into the new server. How should I do this with redis? 

P.S.: I&#39;m not looking to set-up replication. I want to completely migrate the redis server to a new instance.

How do I move a redis database from one server to another?

Say I&#39;ve created a database in pgAdmin, but I want to export a CREATE sql file.

How would I go about generating the dump?

Export a CREATE script for a database

I tried to write the following inner join query using an Oracle database:

     SELECT Employee.EMPLID as EmpID, 
            Employee.FIRST_NAME AS Name,
            Team.DEPARTMENT_CODE AS TeamID, 
            Team.Department_Name AS teamname
     FROM PS_TBL_EMPLOYEE_DETAILS Employee
     INNER JOIN PS_TBL_DEPARTMENT_DETAILS Team 
     ON Team.DEPARTMENT_CODE = Employee.DEPTID

That gives the below error:

     INNER JOIN PS_TBL_DEPARTMENT_DETAILS Team ON Team.DEPARTMENT_CODE = Employee.DEPTID
                                                  *
    ERROR at line 4:
    ORA-00904: &quot;TEAM&quot;.&quot;DEPARTMENT_CODE&quot;: invalid identifier

The DDL of one table is:

    CREATE TABLE &quot;HRMS&quot;.&quot;PS_TBL_DEPARTMENT_DETAILS&quot;
    (
      &quot;Company Code&quot; VARCHAR2(255),
      &quot;Company Name&quot; VARCHAR2(255),
      &quot;Sector_Code&quot; VARCHAR2(255),
      &quot;Sector_Name&quot; VARCHAR2(255),
      &quot;Business_Unit_Code&quot; VARCHAR2(255),
      &quot;Business_Unit_Name&quot; VARCHAR2(255),
      &quot;Department_Code&quot; VARCHAR2(255),
      &quot;Department_Name&quot; VARCHAR2(255),
      &quot;HR_ORG_ID&quot; VARCHAR2(255),
      &quot;HR_ORG_Name&quot; VARCHAR2(255),
      &quot;Cost_Center_Number&quot; VARCHAR2(255),
      &quot; &quot; VARCHAR2(255)
    )
    SEGMENT CREATION IMMEDIATE PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS





ORA-00904: invalid identifier

I need to insert rows into PG one of the fields is date and time with time stamp, this is the time of incident, so I can not use --&gt; current_timestamp function of Postgres at the time of insertion, so how can I then insert the time and date which I collected before into pg row in the same format as it would have been created by current_timestamp at that point in time.


How to insert current_timestamp into Postgres via python

I am using the Ruby on Rails 3.1 pre version. I like to use PostgreSQL, but the problem is installing the `pg` gem. It gives me the following error:

    $ gem install pg
    Building native extensions.  This could take a while...
    ERROR:  Error installing pg:
        ERROR: Failed to build gem native extension.

            /home/u/.rvm/rubies/ruby-1.9.2-p0/bin/ruby extconf.rb
    checking for pg_config... no
    No pg_config... trying anyway. If building fails, please try again with
     --with-pg-config=/path/to/pg_config
    checking for libpq-fe.h... no
    Can&#39;t find the &#39;libpq-fe.h header
    *** extconf.rb failed ***
    Could not create Makefile due to some reason, probably lack of
    necessary libraries and/or headers.  Check the mkmf.log file for more
    details.  You may need configuration options.

    Provided configuration options:
        --with-opt-dir
        --without-opt-dir
        --with-opt-include
        --without-opt-include=${opt-dir}/include
        --with-opt-lib
        --without-opt-lib=${opt-dir}/lib
        --with-make-prog
        --without-make-prog
        --srcdir=.
        --curdir
        --ruby=/home/u/.rvm/rubies/ruby-1.9.2-p0/bin/ruby
        --with-pg
        --without-pg
        --with-pg-dir
        --without-pg-dir
        --with-pg-include
        --without-pg-include=${pg-dir}/include
        --with-pg-lib
        --without-pg-lib=${pg-dir}/lib
        --with-pg-config
        --without-pg-config
        --with-pg_config
        --without-pg_config


    Gem files will remain installed in /home/u/.rvm/gems/ruby-1.9.2-p0/gems/pg-0.11.0 for inspection.
    Results logged to /home/u/.rvm/gems/ruby-1.9.2-p0/gems/pg-0.11.0/ext/gem_make.out

How do I solve this problem?


Can&#39;t find the &#39;libpq-fe.h header when trying to install pg gem

I&#39;m not sure if its standard SQL:  

     INSERT INTO tblA 
     (SELECT id, time 
        FROM tblB 
       WHERE time &gt; 1000)  

What I&#39;m looking for is: **what if tblA and tblB are in different DB Servers**.

Does PostgreSql gives any utility or has any functionality that will help to use `INSERT query with PGresult struct`  

I mean `SELECT id, time FROM tblB ...` will return a `PGresult*` on using `PQexec`. Is it possible to use this struct in another `PQexec` to execute an INSERT command.  

EDIT:  
If not possible then I would go for extracting the values from PQresult* and create a multiple INSERT statement syntax like:

    INSERT INTO films (code, title, did, date_prod, kind) VALUES
        (&#39;B6717&#39;, &#39;Tampopo&#39;, 110, &#39;1985-02-10&#39;, &#39;Comedy&#39;),
        (&#39;HG120&#39;, &#39;The Dinner Game&#39;, 140, DEFAULT, &#39;Comedy&#39;); 

Is it possible to create a prepared statement out of this!! :(

postgresql: INSERT INTO ... (SELECT * ...)

I would like to use the psql &quot;\copy&quot; command to pull data from a tab-delimited file into Postgres.  I&#39;m using this command:

    \copy cm_state from &#39;state.data&#39; with delimiter &#39;\t&#39; null as ;

But I&#39;m getting this warning (the table actually loads fine):

    WARNING:  nonstandard use of escape in a string literal
    LINE 1: COPY cm_state FROM STDIN DELIMITER &#39;\t&#39; NULL AS &#39;;&#39;
    HINT:  Use the escape string syntax for escapes, e.g., E&#39;\r\n&#39;.

How do I specify a tab if &#39;\t&#39; is not correct?


Content Type	Original Author	Original Content on Stackoverflow
Question	Sachin R	View Question on Stackoverflow
Solution 1 - Mysql	Frosty Z	View Answer on Stackoverflow
Solution 2 - Mysql	Deckard	View Answer on Stackoverflow
Solution 3 - Mysql	C.T	View Answer on Stackoverflow

Migrate database from Postgres to MySQL

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

ActiveRecord Rails 3 scope vs class method

What's the difference between the IN and MEMBER OF JPQL operators?

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